Fry bacon for 10 minutes, until outside is crispy and brown.

In large, deep skillet over medium-high heat, heat olive oil and saute spinach until wilted. Set aside.

In another large skillet, melt butter over medium-high heat until melted. Carefully crack eggs into skillet and fry until yolk is done.

Assemble sandwiches as follows: doughnut bottom, spinach, egg, slice of cheese, bacon, doughnut top.